1. Field of the Invention
The invention relates to railway rolling stock and consists particularly in a railway vehicle such as a locomotive having at least three swiveling trucks, and more particularly in an intermediate truck for such a vehicle.
2. The Prior Art
In the prior art, F. L. Alben U.S. Pat. No. 2,610,586 discloses trucks for three-truck locomotives in which the body bolsters transversely slidably receive a member swivelly connected to the truck frames and spring-supported thereon and slidably supporting the underframe, the last-named member being centered by horizontal transversely extending centering springs on the end trucks and being freely movable transversely on the middle truck to provide unrestricted lateral motion for operation on curved track. C. W. Kell et al U.S. Pat. No. 2,829,605 discloses a truck for three-truck locomotives in which a truck bolster is laterally movable in a pocket in a truck frame and swivels with respect to the underframe and has downwardly facing side bearings slidably engaging the truck frame and upwardly facing side bearings slidably engaging the underframe, horizontal springs centering the bolster transversely of the truck frame on the end trucks being omitted from the intermediate truck or trucks so as to accommodate freely necessary lateral excursions of the middle trucks during curved track operation. Keith L. Jackson U.S. Pat. No. 4,231,926 discloses trucks in which a bolster is spring-supported on the truck frame to provide both lateral and vertical deflection. On the end trucks, the bolster engages a swivel member on the underframe and is incapable of lateral movement with respect to the underframe, while on the intermediate trucks the bolster is connected to the underframe by a Watts linkage so as to permit substantial lateral as well as swivel movement between side bearing surfaces on the bolster and downwardly facing bearing surfaces on the underframe, such that normal lateral movement of the intermediate truck relative to the locomotive body is accommodated through lateral deflection in the bolster springs and lateral excursions are accommodated by transverse sliding of the upwardly facing side bearings on the bolster with respect to downwardly facing loading pads on the underframe.